Chair structure and method for making same



Sept. 14, 1965 J. G. STEVENS CHAIR STRUCTURE AND METHOD FOR MAKING SAMEFiled June 1'7, 1963 3 Sheets-Sheet l JOEL e. STEVENS INVENTOR.

ATTORNEYS BY Iu LL Sept. 14, 1965 G. STEVENS 3,206,251

CHAIR STRUCTURE AND METHOD FOR MAKING SAME Filed June 17, 1963 3Sheets-Sheet 2 JOEL G. STEVENS INVENTOR.

m'm rm ATTORNEYS Sept. 14, 1965 J. a. STEVENS CHAIR STRUCTURE AND METHODFOR MAKING SAME Filed June 17, 1963 3 Sheets-Sheet 3 FIG FIG .9

JOEL G. STEVENS INVENTOR.

ATTORNEYS United States Patent 3,206,251 CHAIR STRUCTURE AND METHUD FURMAKING SAL IE Joel G. Stevens, 5006 41st SW., Seattle, Wash. Filed June17, 1963, Ser. No. 288,3tl8 4 Claims. (Cl. 297-457) This inventionrelates to a new and novel chair structure and method for its making,and more particularly to a chair structure and method directed to achair shell made of fiat, relatively thin, sheet material and which doesnot have a supported back but which does not have a supported back butwhich depends on its naturally formed curves for strength andflexibility.

Many, if not most, of the chair shells which are known today aresingularly complex devices. Their designs and hence their manufacture isinvolved and expensive. For instance, compound and other artificallyformed curves require molding and forming equipment usually found inelaborate production lines. The nature or" the hitherto known designsalso necessitates specially designed leg structures. In most of theother types and designs with which applicant has become familiar the legstructure for the chair has also employed a support for the back portionof the chair shell. With no support a one piece, rigid molded andnonfiexible shell usually requires specially designed leg mountings toachieve and flexibility in the structure as a whole. Apparently it hasbeen assumed in all cases that a back support for the chair shell isnecessary.

This invention is designed to provide a chair shell and the method forits making which represent a significant advance in the chairmanufacturing industry. This invention overcomes numerous of thedisadvantages of other chairs because of its extreme simplicity. Inessence, this invention involves cutting a predetermined pattern designfrom a piece of sheet material, slitting the sheet or the pattern at apredetermined location, and then overlapping the portions on each sideof the slit to draw the pattern into a natural or free formconfiguration around the inside end of the slit. Such structure andmethod result in the formation of a form which most closely resembles acone generated generally around the inside end of the slit or cut. Inany event there are no obvious stress points or areas which would, andwhich usually do, result from artifically formed curves. The formedsingle sheet pattern is attached to practically any kind of legstructure which does not involve means for supporting the back portionof the chair shell. The overlapping, intended primarily for the seat,increases the chair strength twofold in an area which might otherwisenot be strong enough. At the same time the back and sides, being formedof single thickness material, are more fiexible than the seat which isprecisely the result desired.

Accordingly it is one of the many objectives and purposes of thisinvention to provide a chair incorporating a maximum of design balance,comfort and strength.

Another object of this invention is to supply a chair which is simple indesign and to which many, if not most of the conventionally known legstructures can be adapted.

A prime object and purpose of this invention is to furnish a chairstructure and method for its making which because of design simplicityrequires no complex, costly time consuming production equipment andwhich is therefore extremely inexpensive to produce.

Another object of this invention is to provide a chair structure andmethod for its making which, in utilizing the natural curves of a cone,enable an infinite number of design variations on the basic concept bychanging the pattern layout.

3,206,251 Patented Sept. 14, 1965 ice Still another object of thisinvention is to supply a chair structure which is light in weight andwhich can be partially finished so as to provide shipping advantages inreduced weight and compact packaging.

Yet another object of this invention is to furnish a chair structurewhich is rugged and durable even though made of thin sheet material andeven though it lacks supporting means for the back portion of the chairshell.

A further object of this invention is to provide a chair structure andmethod for its making in which the comfort characteristics are derivedfrom the fact that the user does not need to distribute his body in thechair to accommodate the chair design, but which allows the chair toflex and adjust itself to the body of the user.

These and other objects and advantages will become apparent upon readingthe following specification, claims and accompanying drawings, all ofwhich form a part of this disclosure.

In the drawings:

FIGURE 1 is a view in perspective of a chair shell formed according tothis invention which for purposes of illustration only has been shown tobe mounted on a pedestal type base or leg structure;

FIGURE 2 is a side view of the chair of FIGURE 1 which also illustratesthat the angle of the chair back in relation to the chair seat may bevaried considerably;

FIGURE 3 shows how a pattern for this invention may be laid out in itspurely flat state;

FIGURE 4 shows a side view of a chair which may be formed from thepattern of FIGURE 3, and which for purposes of illustration shows adifferent leg structure;

FIGURE 5 shows an alternative pattern in which the point at the back ofthe chair seat is de-emphasized by making a diiferent cut in thepattern;

FIGURE 6 shows in perspective what a chair formed from the pattern ofFIGURE 5 would look like;

FIGURE 7 shows how emphasis may be taken off the point at the rear ofthe seat depending upon the nature of the cut at the inner end of theslit;

FIGURE 8 shows a difierent pattern in which the chair back is slit inorder to form a double back instead of a double seat;

FIGURE 9 shows a chair formed from the pattern of FIGURE 8 and suggestsalong with FIGURE 8 the extreme flexibility of the method involved inthis invention;

FIGURE 10 illustrates a side view of a single piece pattern which couldbe designed to include the secondary cone structure at the top of thechair shell back for shade or for holding a reading light, if desired;and

FIGURE 11 shows a front view of an alternative embodiment formedbasically from the pattern of FIGURE 3 but in which the seat has beenflattened rather than allowed to follow the natural curves generatedaround the point at the back of the seat.

Referring now to the drawings, it will be seen that the chair shell,generally designated by the number 10, is cut to a predetermined patternfrom a sheet of flat, relatively thin material such as aluminum or resinreinforced fiberglass. Either of these materials can be used, althoughthe plastic shell should use a pattern with a fairly large hole at theinner end of the seat. The thickness of the sheet material takes nodefinite or specific dimensions. However, it has been found that .030gauge tempered aluminum sheet has been incorporated very favorably inthose chairs already produced. Likewise a plastic shell, which besidesfiberglass, could include a wide range of plastic material would be inthe area of about /s of an inch thick. The seat portion, as can be seenwitth reference to FIGURE 4, flares outwardly and away from the generalarea at the base of the back portion 12 in the form of reverse curveedge portion 42.

The edge portion 42 terminates at points 44. A generally semi-circularedge as at 38 and 46 is cut from one point 44 to the other point 44.Curvative of the edges 38 and 40 is determined by the fact that thoseportions of the chair shell defining said edges will overlap and musttherefore place said edges as close together as possible.

The pattern can be considered as symmetrical on each side of alongitudinal axis running along a center line taken through the back andseat portions. When the pattern has been out along the general linesmentioned above a hole 34 is cut at a predetermined point on thelongitudinal axis at a predetermined distance from the front edge of theseat. The pattern is slit from the front edge to the hole along saidaxis to define the seat section 18 with a slit edge 20 and a seatsection 22 with a slit edge 21. Thus seat section 22 has front edge 49while seat section 18 has front edge '38. The hole '34 may be of anysize and therefore its dimensions are not to be considered limiting. Thepurpose in deemphasizing the point of the chair with a larger hole, asin FIGURE 7, is to reduce possible injurious effects by reducing theprojection of models with little or no covering. Also for chairs leftoutside, moisture and rain are easily drained oft. For purposes ofillustration a hole 34 one inch in diameter may be cut on thelongitudinal axis sufficiently far from the front edge of the seat toprovide adequate =body support or seat area and yet at the same time toallow for the fact that the body will not occupy a space of severalinches which is most immediate to hole 34-. As can be seen by referenceto FIGURE 3, the hole may be larger and of a shape other than round asindicated by the hole 36 in dotted lines. Hole 36 is given theillustrated shape so as to present a curved side view rather than astraight line side view thus avoiding abrupt edges.

When the pattern has been cut and slit as indicated one seat section, asfor instance 18, is drawn over and lapped on the other seat section 22.As a result of this overlapping the pattern will dr-aw itself intonatural curves around the hole '34 which, in effect, is the point orapex of a cone. In theory all curves are generated in the form of aperfect cone. As practical matter, however, the curves are not perfectbut do very closely resemble natural cone curves. The overlapping ofsections 18 and .22 is limited in the extreme by the desire to have anangle of no less than 90 degrees between the back and seat surfaces.However, it is best not to overlap to such an extent that the seat andthe back achieves such an angle to each other. When the desired anglebetween the seat and the back has been realized, four holes are drilledor formed through the overlapping seat sections 18 and 22. As can beseen, particularly with reference to FIGURE 1, two holes are drillednear the slit edge '20 of top seat section 18 and two holes are drilledor otherwise formed near the underside slit edge 20 of seat section 22.Two

holes are located near the front edge of the seat While two holes aredrilled relatively close to hole 34. Securing means 24 and 26 and 28 and29 are inserted through the holes to hold the seat sections in theiroverlapping relationship and to secure the entire seat shell or pattern10 to the leg structure which for purposes of this illustration has beenshown to be pedestal 32.

The leg structure or chair shell supporting structure is contemplatedonly in its broadest and most encompassing meaning. Once the overlappinghas been achieved, the holes formed and the securing means insertedthrough the holes and into the base or leg supporting structure, thechair is essentially completed. It is only necessary then to use aproper hand tool to de-burr and to round the edges and to do whateverfinishing is desired. This particular chair shell lends itself veryreadily to upholstering with any kind of material from a thin fabric toa thick foam rubber or other cushioning type covering. Any type ofcovering or upholstering is easily provided by simply cutt ng it to theshell pattern. Stretching and pulling are avoided and the problems ofaccommodating the covering to compound curves and irregular lines andsurfaces are also not encountered. Thus adhesives may be used veryeffectively.

FIGURES 5 and 6 suggest a way in which the sharp point effect of a smallhole 34 may be eliminated by a slightly different cut in that area ofthe pattern surrounding the inside end of the slit. A pattern 50 has aback portion 51 and a seat area which is generally in agreement with theoutlines of pattern 10. The slit is made defining slit edges '54 and 56but terminating as at 52 at a predetermined point on the longitudinalaxis. At a point several inches from the terminal end 52 of the slit acircular cut is made extending in a generally round curve forapproximately 270 degrees or a circle. The cut or slit 62 is made withterminal end 52 as the generating center thus defining the centersection 64 which is still integrally connected to the overall pattern.When this alternative structure is finished with the seat sectionsoverlapping the center section 64 has cut off a larger portion of thepoint of the cone than the one inch hole. The center section 64 ineffect itself assumes a slightly conical shape around terminal end 52.This particular pattern shows some of the flexibility that is connectedwith the use of this method and structure. The pattern or chair shell 59can be attached to the leg structure 66. If desired the outer ends ofthe seat slit may be rounded oil as 58 and 69 for aesthetic reasons, andto eliminate sharp projections so that the lapped portions slide moreeasily into place.

FIGURES 8 and 9 indicate that the pattern may have a double thickness onits back portion if desired to strengthen the back or mount somethingthereon. Note that in pattern 7 (9 there are two back sections 74 and76. Hole 82 is formed in the pattern on the longitudinal axis thereofand a slit is made from between the two back sections to said hole 82.The seat portion 72 is designed to its finished shape as the backsection 12 is in pattern 10. Note that slit edges 78 and Sit in thefinished chair extend from the point generally upwardly and outwardly tothe transition curve between the seat and back portion. Finally thecompleted chair shell is secured to a leg supporting structure 84. Theextra variability of design indicated by these two figures gives a chairshell with seamless seat and side portions. The double thickness backallows the shell to be fastened to a wall for stationary use.

FIGURE 10 shows further the versatility of the free form cone design. Apattern 9t) has aform similar to that of pattern It) but also has a hoodsection 92 formed around a hole at point 94.

FIGURE 11 shows that the seat of pattern 10 may be flattened ifpreferred to the natural curve. Some forming would then take place inthe seat portion as at 9.6 and 98 in the area next adjacent to slitedges 20 and 21.

This invention, particularly as shown in FIGURES 1 to 7, l0 and 11provide a chair which allows a maximum of free movement to its occupant.Thus, side-toside, back-and-forth, and twisting motion are permitted theuser. The amount of movement allowed can be controlled by leverage dueto the height of the back, angle of tilt of back with respect to theseat, and by the extent of overlap in the seat.

The foregoing is considered as illustrative only of the principal ofthis invent-ion and hence it is not desired to limit the invention tothe exact structure and method shown and described. Accordingly allsuitable modifications and equivalents may be resorted to, fallingwithin the scope of the invention.

What is claimed is:

1. A chair structure, comprising: a chair shell made of a single sheetof flat, relatively thin, essentially rigid material, said shell beingformed from a pattern in which sections of said patterns are overlappedto define a double thickness seat area leaving the side portionsadjacent said seat area and the back portion of said shell in singlethickness, said shell being formed on natural, essentially conelikecurves around a hole means centered with respect to the side edges ofsaid shell and from which hole means said seat, side portions and backportion are generated; and a chair shell supporting structure attachedto said shell by securing means designed to be inserted through saiddouble thickness seat portion for maintaining said double thicknessseat, said supporting structure being entirely free of means forsupporting said back portion of said shell.

2. A chair structure, comprising: a chair shell made of a single sheetof fiat, relatively thin, essentially rigid material, said shell beingformed from a pattern in which sections of said pattern are overlappedto define a double thickness seat area leaving the side portionsadjacent the seat area and the back portion of said shell in singlethickness, said shell being formed on natural, essentially conelikecurves around a hole means centered with respect to the side edges ofsaid shell and from which hole means said seat, side portions and backportion are generated; and a chair shell supporting structure attachedto the underside of said shell by securing means, said securing meansbeing inserted through said double thickness seat and said supportingstructure being entirely free of means for supporting said back portionof said shell.

3. A chair structure, comprising: a chair shell made of a single sheetof flat, relatively thin, essentially rigid material, said shell beingformed from a pattern having a back portion, a seat area and sideportions adjacent said seat area, said pattern having sections which areoverlapped to define a double thickness seat area leaving the sideportions adjacent the seat area and the back portion of said shell insingle thickness, said shell being formed on natural, essentiallycone-like curves around a hole means centered with respect to the sideedges of said shell and from which hole means said seat, side portionsand back portions are generated; and a chair shell supporting structureattached to the underside of said shell by securing means insertedthrough said double thickness seat portion, said supporting structurebeing entirely free of means for supporting said back portion of saidshell.

4. A chair structure, comprising: a chair shell made of a single sheetof flat, relatively thin, essentially rigid material, said shell beingformed from a pattern in which sections of said pattern are overlappedto define a double thickness back area leaving the side portionsadjacent the seat area and the seat portion of said shell in singlethickness, said shell being formed on natural, essentially cone-likecurves around a hole means centered with respect to the side edges ofsaid shell and from which hole means said seat, side portions, and backportion are generated; a chair shell supporting structure attached tothe underside of said shell by securing means; and securing meansinserted through said double thickness back; and said supportingstructure being entirely free of means for supporting said back portionof said shell.

References Cited by the Examiner UNITED STATES PATENTS 401,302 4/89Purdy 297-445 2,541,835 2/51 Saarinen 297-457 2,606,601 8/52 Saarinen297418 2,939,517 6/60 Saarinen 297-418 3,009,740 11/61 Nelson et a1.297457 FRANK B. SHERRY, Primary Examiner.

1. A CHAIR STRUCTURE, COMPRISING: A CHAIR SHELL MADE OF A SINGLE SHEETOF FLAT, RELATIVELY THIN, ESSENTIALLY RIGID MATERIAL, SAID SHELL BEINGFORMED FROM A PATTERN IN WHICH SECTIONS OF SAID PATTERNS ARE OVERLAPPEDTO DEFINE A DOUBLE THICKNESS SEAT AREA LEAVING THE SIDE PORTIONSADJACENT SAID SEAT AREA AND THE BACK PORTION OF SAID SHELL IN SINGLETHICKNESS, SAID SHELL BEING FORMED ON NATURAL, ESSENTIALLY CONELIKECURVES AROUND A HOLE MEANS CENTERED WITH RESPECT TO THE SIDE EDGES OFSAID SHELL AND FROM WHCIH HOLE MEANS SAID SEAT, SIDE PORTIONS AND BACKPORTION ARE GENERATED; AND A CHAIR SHELL SUPPORTING STRUCTURE ATTACHEDTO SAID SHELL BY SECURING MEANS DESIGNED TO BE INSERTED THROUGH SAIDDOUBLE THICKNESS SEAT PORTION FOR MAINTAINING SAID DOUBLE THICKNESSSEAT, SAID SUPPORTING STRUCTURE BEING ENTIRELY FREE OF MEANS FORSUPPORTING SAID BACK PORTION OF SAID SHELL.